This invention relates to a porcelain (particularly dielectric) composition for low temperature sintering comprising lead ferro-tungstate, lead titanate and lead ytterbium-niobate as three major components, and if necessary together with manganese dioxide as a secondary component.
Heretofore, barium titanate (BaTiO.sub.3) has been used as a major component for a material having a high relative dielectric constant and sinters at a temperature of 1300.degree. to 1400.degree. C. In order to enhance a relative dielectric constant of barium titanate at room temperature or to improve temperature characteristics of barium titanate, there is employed a process for adding various oxides such as strontium titanate (SrTiO.sub.3), calcium stannate (CaSnO.sub.3), calcium titanate (CaTiO.sub.3), etc., to barium titanate. But since the sintering temperature is as high as 1300.degree. to 1400.degree. C. as mentioned above, the resulting barium titanate composition has disadvantages in that operations should be conducted at high temperatures, an expensive metal such as platinum, palladium, or the like which are suitable for said sintering temperature should be used as inner electrode, particularly in the case of forming a multilayer capacitor.
Therefore, it has long been desired to find out a porcelain composition which can be sintered at lower temperatures, particularly 1000.degree. C. or lower, in the case of forming particularly multilayer capacitors, so as to give various remarkable advantages such as the use of less expensive metals, e.g., alloys containing silver as a main component, as inner electrode in place of expensive metals mentioned above, the use of a less expensive furnace because of the low sintering temperature, and saving of heat energy.